| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Endocrinology, Vol 125, 2532-2539, Copyright © 1989 by Endocrine Society
ARTICLES |
BJ Canny, JW Funder and IJ Clarke
Medical Research Centre, Prince Henry's Hospital, Melbourne, Australia.
Hypophysial portal circulation levels of immunoreactive (ir) CRF, immunoreactive arginine vasopressin (ir-AVP), and systemic ir-ACTH and cortisol were determined in dexamethasone-infused (20 micrograms/h) ewes, both under basal conditions and in response to audiovisual and hypoglycemic stress. Glucocorticoid infusion lowered mean basal levels of ir-CRF (P less than 0.05), ir-ACTH (P less than 0.05), and cortisol (P less than 0.05), but not of ir-AVP. Audiovisual stress led to coordinate release of ir-AVP and ir-CRF, and although the hypothalamic response to this stress was not altered in dexamethasone (DEX)-infused sheep, the pituitary-adrenal response was blocked, suggesting that glucocorticoids act on the pituitary rather than on higher centers to inhibit this response. In contrast, hypoglycemia led to preferential release of ir-AVP over ir-CRF, and DEX infusion delayed and inhibited both hypothalamic and pituitary responses. Ketamine injection also led to preferential release of ir-AVP, but neither the hypothalamic nor pituitary-adrenal responses were affected by DEX infusion. These results suggest that different stressors evoke different patterns of hypothalamic secretagogue release, and that glucocorticoids act in a site-specific fashion to regulate the hypothalamo-pituitary-adrenal responses to stress.
This article has been cited by other articles:
![]() |
D. Engler, E. Redei, and I. Kola The Corticotropin-Release Inhibitory Factor Hypothesis: A Review of the Evidence for the Existence of Inhibitory as Well as Stimulatory Hypophysiotropic Regulation of Adrenocorticotropin Secretion and Biosynthesis Endocr. Rev., August 1, 1999; 20(4): 460 - 500. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. R. de Kloet, E. Vreugdenhil, M. S. Oitzl, and M. Joëls Brain Corticosteroid Receptor Balance in Health and Disease Endocr. Rev., June 1, 1998; 19(3): 269 - 301. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |